1. Field of the Invention
The present invention relates to a pivotal shaft structure, and particularly to a pivotal shaft assembly for a plane display so as to make an upward inclining angle or multi-directional rotations of the plane display possible.
2. Description of Related Art
Because a plane display such as liquid crystal display, liquid crystal television or plasma television has special features of lightness, thinness, shortness and smallness, the plane display has become a major product of display instead of the traditional CRT gradually. In order to have an optimum visual angle, the ordinary vertical type plane display is provided with a pivotal shaft device between the main body and the base thereof such as rotational shafts, which are disposed at both lateral sides of the display. In this way, the main body of the display can be adjusted an inclining angle forward or backward with respect to the base.
Considering available limited occupied space, some plane displays have to be hung to a stationary object such as a screen system in an office, an exhibition wall or a public open space and it is done with a standardized connecting plate being joined to the rear side of the display. The rear side of the connecting plate is then connected to a rotational shaft device, which is capable of swing along a transverse direction and a longitudinal direction respectively. Finally, the display can be adjusted an inclined angle forward or backward and a rotational motion to the right or the left.
However, it is not possible to comply with the need of multi-directional adjustments with only a rotational motion to the right or to the left. Thus, a spherical nest device, which is frequently used in lighting tools for multi-directional adjustments, is utilized by the suppliers and placed at the front side of the pivotal shaft structure and a lateral side of the spherical nest device is disposed next to one of the rotational shaft device such that the rotational shaft devices can be operated to adjust the frictional torque by way of double directional threaded connection. But, once one of the lateral sides is not screwed up tightly, it is often to occur a phenomenon of loosening to result in undesirable effect.